Corrupted Control Template : well there’s an error I’ve not seen before!

There I was .. doing some (behind the scenes) coding work on an accessibility project….
 
and I got this …
 
Corrupted Control Template. Please check RenderingTemplate of RichImageField in the control template ascx file.

 
What caused it???

 
Well … it was admittedly totally my fault. I deleted one of the OOB files in ControlTemplates .. specifically "DefaultTemplates.ascx".
 
We were working with the field control rendering (like text box, drop-down list .. etc) and I accidentally deleted one of the files.
 
Still .. at least I’ll know what it is next time 😀